Azure number of VMs, more than you subscribed, 1 domain names are needed for this configuration, but only 0 domain names (of 20) remain in your subscription.Request an increase

while working in azure, I was trying to create a vm and got below error
in new portal
Azure number of VMs, more than you subscribed, 1 domain names are needed for this configuration, but only 0 domain names (of 20) remain in your subscription.Request an increase

in old portal

this means, that you have exceeded the maximum number of VMs you can create under your subscription. this is good has been done from MS side, that there is an alert in a certain range.

so to get this you need to request to MS to increase the max number of VMs you can have, check if this has any relation with the number of cores that you can have.
cause the initial assigned cores you might not have used for all 20 VMs.

hope this will help.

Regards,
Yes.Sudhanshu